Compositions for making substrates, in particular fibrous substrates, such as textile, oil- and water repellent have been long known in the art. When treating fibrous substrates and in particular textile such as apparel, it is desired that the textile retains its look and feel as much as possible. Therefore, the composition should normally not contain components that would affect the look of the product, i.e., the treatment should be substantially invisible to the unaided human eye. Also the feel of the substrate should preferably be substantially unaffected. Typically this means that only low amounts of the solids of the composition can be applied. Accordingly, an oil- and/or water repellent composition should be highly effective in rendering a substrate repellent.
Commercially available oil- and/or water repellent compositions are typically based on fluorinated compounds that have a perfluorinated aliphatic group. Such compositions are also described in, for example, U.S. Pat. No. 5,276,175 and EP 435 641. The commercial success of this type of compositions can be attributed to their high effectiveness. Fluorinated compounds based on perfluorinated ether moieties have also been described in the prior art for rendering fibrous substrates oil- and/or water repellent. For example, perfluorinated polyether compounds have been disclosed in EP 1 038 919, EP 273 449, JP-A-04-146917, JP-A-10-081873, U.S. Pat. No. 3,536,710, U.S. Pat. No. 3,814,741, U.S. Pat. No. 3,553,179 and U.S. Pat. No. 3,446,761.
U.S. Pat. No. 3,553,179 discloses acrylate type esters of perfluoropolyoxa-alkaneamidoalkyl alcohols and homo- and copolymers derived therefrom and the treatment therewith of fabrics to render the latter oil- and/or water repellent. According to the teaching of this patent, the best results are obtained when the polymer is derived from monomers in which the perfluorinated polyether moiety has a fairly low molecular weight. Such compounds however have the disadvantage that perfluorinated degradation products may form or perfluorinated residuals from the preparation of polymer may be present that have a low molecular weight. These compounds can be present in substantial amounts and may not eliminate quickly from living organisms and are therefore environmentally less desired. Additionally, the examples in this patent indicate that fairly high levels of the fluorinated polymer need to be applied on the fabric and even then, the compositions do not always seem to provide oil repellency properties.
Accordingly, it is a desire to find fluorochemical compositions based on a perfluorinated polyether compound that can provide good to excellent oil- and/or water repellency properties to a fibrous substrate. Preferably, the fluorochemical composition is capable of providing durable oil- and/or water repellency properties to a fibrous substrate such that a treated fibrous substrate can substantially maintain the repellency properties even after several washing cycles. Preferably a fibrous substrate treated with the fluorochemical composition has a soft feel, preferably the feel of a treated fibrous substrate is either the same or softer compared to the untreated fibrous substrate. It is a further desire that the fluorochemical compositions can be easily and efficiently manufactured at a low cost. It is further desired to find compositions that have environmentally beneficial properties.